Partial replacement of carbon black with graphene in natural rubber/butadiene rubber based tire compound: Investigation of critical properties

Natural rubber and Polybutadiene rubber based formulations with carbon black as the reinforcement are used extensively for tire applications. Carbon black is a very good reinforcing material and it has a lot of applications in different types of tire components. There were many attempts to replace fully or partially it with other materials such as silica, graphite, nanocellulose, mica without compromising on the texture and properties of the natural rubber based formulations. Herein, an attempt is made to partially replace carbon black with modified graphene in various amounts (0, 1, 2.5 and 5 phr) keeping the total amount of filler content as 55 phr. The multilayered graphene platelets were characterized by Raman spectroscopy and scanning electron microscopy (SEM) and the presence of oxygen on the surface was established through EDS analysis. The prepared compounds were analyzed with respect to cure characteristics, rheological measurements, mechanical properties, bound rubber content and rolling resistance. The formulations with 2.5 phr of graphene is considered as the optimum concentration of replacement as it showed better properties compared to other loadings. The uncured samples showed Payne effect at low strain measurements which indicates the effectiveness of the replacement of carbon black with graphene. The increase in elongation at break and the bound rubber content for formulations with graphene replacement indicated an effective interaction between the elastomer and the modified graphene. Furthermore, scanning electron microscopy and micro computed tomography measurements of the samples showed the enhanced distribution of the fillers in the formulations. Another important aspect is related to the decrease in rolling resistance of the compounds which show that the hysteresis has decreased.

Automated summary

Graphene can partially replace carbon black in rubber formulations for tires, improving properties and texture, enhancing interaction between elastomer and fillers, and reducing rolling resistance.